Background: Metabolic bariatric surgery (MBS) reduces the risk of new-onset hypertension; however, it is unclear whether this effect varies according to patient sex, age, or socioeconomic background. This study aimed to assess the risk of new-onset arterial hypertension after MBS, with a special focus on these patient characteristics.

Methods: This follow-up study with matched controls was nested in a large employee cohort, the Finnish Public Sector study, consisting of individuals with no hypertension at baseline. For each patient who underwent laparoscopic MBS between 2008 and 2016, two propensity-score matched controls were selected from individuals hospitalized with a diagnosis of obesity or individuals with self-reported severe obesity [body mass index (BMI) ≥ 35 kg/m 2 ] but no recorded history of MBS. Cases of new-onset hypertension were identified via linked electronic health records from the national health registries until December 31, 2016.

Results: The study included 912 patients and 1780 matched controls. The rate of new-onset hypertension per 1000 person-years was 2.8 in the surgery group and 9.6 in the control group, with a rate ratio of 0.29 (95% confidence intervals 0.15-0.57) and a rate difference of -6.8 (95% confidence intervals -9.6 to -4.0) per 1000 person-years. No significant differences in rate reduction after MBS were observed to be associated with patient sex, age, or socioeconomic status.

Conclusion: Metabolic bariatric surgery reduces the risk of new-onset arterial hypertension across all age-, sex-, and socioeconomic subgroups.